Oskar Schell (Thomas Horn), a grieving 11-year-old boy in the unsettling, whimsy-glutted remember-9/11-at-the-holidays drama Extremely Loud & Incredibly Close, refers to when his father died only as ”the Worst Day.” The designation is much more to the point than ”the day the Twin Towers of the World Trade Center were destroyed by terrorists, killing everyone inside, including Oskar’s nice Dad, generously played by Tom Hanks.” A year after the Worst Day, while his sad Mom (an earnest Sandra Bullock) is at work, Oskar discovers a key hidden among his dead dad’s belongings. Convinced that the key will open something important, something that will reveal a message — father and son used to play at elaborate clue-filled ”reconnaissance expeditions” — the boy begins scouring the city for the key’s owner. For a time, he is accompanied by a mute old man known only as the Renter (Max von Sydow, giving a great acting lesson in wordless physical action) because he rents a room from Oskar’s grandma (Zoe Caldwell). The Renter communicates by writing in a little notebook. For convenience, he also keeps YES inked on his left palm and NO on his right, and he flashes his hands, when appropriate, like a mime. Among those who can’t help Oskar — as an extra challenge, the boy could reasonably be diagnosed on the autism spectrum — are an unhappy couple played by Viola Davis and Jeffrey Wright.

A polarizing load of quirkiness in Extremely Loud gunks up (at least for this hometown mourner; your results may vary) what is at heart a piercing story: Here’s a tale that compacts the grief of an entire world, country, city, and thousands of loved ones left behind into the pain of one vulnerable, fictional boy. The gunk is not, in itself, the movie’s fault. Those narrative curlicues are embedded in Jonathan Safran Foer’s 2005 novel of the same name. (There, a reader can find a photo of palms marked YES and NO.) Indeed, the cinematic translation provided by Stephen Daldry (a pro at directing boys after Billy Elliot) is about as 9/11-respectful and eager to please as one can want with such a sugared premise. It will never get any easier, nor should it, to see images of the towers ? in flames, or of human beings falling to their deaths; at least Daldry is prudent in his use of sacred footage.

But Alexandre Desplat’s score — which ? is full of musical cues to the audience to ? feel sad here! — only adds to the distraction. Young Thomas Horn is a former Jeopardy! Kids Week winner and acting novice. ? He may have been plucked to play Oskar because of the inherent solemnity and mournfulness that can be read in his sweet features — and he does everything Daldry wants him to. But muffled by the fanciful nature of Oskar’s little adventures, the ? pain of 9/11 doesn’t feel nearly as loud or close as I need it to. B?